Electromagnetic Bicycle Damper (EMBR)
Fall 2025 - Spring 2026
Designed the electromagnet and flux path for a semi-active MR-fluid mountain bike damper, sponsored by ARUS MR Tech, that matched commercial forks on weight at a lower price
Details
- Owned the electromagnet design and calculation verification within an 8-person interdisciplinary team, sponsored by ARUS MR Tech, that retrofitted a production front suspension fork with a semi-active MR damper; the completed fork matched commercial semi-active forks (RockShox Flight Attendant, Fox Live Valve) on weight while undercutting them on price
- Designed and validated the internal electromagnetic coil, using a 26 AWG copper coil and steel core operating at 20 W and 2 A to generate an estimated peak 0.15 T magnetic field across a 2.5 mm radial gap
- Modeled magnetic field strength and spatial geometry using the Biot-Savart law and complete elliptic integrals in Python, orienting field lines perpendicular to fluid flow to maximize yield stress activation
- Designed the magnetic flux path through steel damper components so the field crosses the annular flow gap perpendicular to fluid motion, switching the MR fluid from Newtonian behavior to a Bingham plastic that stiffens the damper on demand, while balancing space, power draw, and heat generation
